/*
 * Copyright 2002-2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.http.client;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.util.StreamUtils;

import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.List;
import java.util.Map;

/**
 * {@link ClientHttpRequest} implementation that uses standard J2SE facilities to execute streaming requests.
 * Created via the {@link SimpleClientHttpRequestFactory}.
 *
 * @author Arjen Poutsma
 * @see SimpleClientHttpRequestFactory#createRequest(java.net.URI, HttpMethod)
 * @since 3.0
 */
final class SimpleStreamingClientHttpRequest extends AbstractClientHttpRequest {

    private final HttpURLConnection connection;

    private final int chunkSize;

    private OutputStream body;

    private final boolean outputStreaming;


    SimpleStreamingClientHttpRequest(HttpURLConnection connection, int chunkSize,
                                     boolean outputStreaming) {
        this.connection = connection;
        this.chunkSize = chunkSize;
        this.outputStreaming = outputStreaming;
    }

    public HttpMethod getMethod() {
        return HttpMethod.valueOf(this.connection.getRequestMethod());
    }

    public URI getURI() {
        try {
            return this.connection.getURL().toURI();
        } catch (URISyntaxException ex) {
            throw new IllegalStateException("Could not get HttpURLConnection URI: " + ex.getMessage(), ex);
        }
    }

    @Override
    protected OutputStream getBodyInternal(HttpHeaders headers) throws IOException {
        if (this.body == null) {
            if (this.outputStreaming) {
                int contentLength = (int) headers.getContentLength();
                if (contentLength >= 0) {
                    this.connection.setFixedLengthStreamingMode(contentLength);
                } else {
                    this.connection.setChunkedStreamingMode(this.chunkSize);
                }
            }
            writeHeaders(headers);
            this.connection.connect();
            this.body = this.connection.getOutputStream();
        }
        return StreamUtils.nonClosing(this.body);
    }

    private void writeHeaders(HttpHeaders headers) {
        for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
            String headerName = entry.getKey();
            for (String headerValue : entry.getValue()) {
                this.connection.addRequestProperty(headerName, headerValue);
            }
        }
    }

    @Override
    protected ClientHttpResponse executeInternal(HttpHeaders headers) throws IOException {
        try {
            if (this.body != null) {
                this.body.close();
            } else {
                writeHeaders(headers);
                this.connection.connect();
            }
        } catch (IOException ex) {
            // ignore
        }
        return new SimpleClientHttpResponse(this.connection);
    }

}
